The force applied is equal to the weight added in each trial plus the force exerted by the Earth's magnetic field. To cancel out the effect of the Earth's field, we need to compute the geometric mean of the forward and reverse currents: The geometric mean is the square root of the product of the two currents. By using this current, the only force in consideration is the weight force. At balance, this force is equal to the force the two wires exert on one another.
Compute the geometric means for each of your three trials.